The invention concerns a process for granulating chemical products. More in detail, it relates to a process for granulating chemical products, in particular fertilizers (according to which process the granules are caused to grow by stratification), by spraying onto the granules, a concentrated solution (or an aqueous suspension or a melt) containing the product to be granulated.
It is known, from U.S. Pat. No. 4,478,170, to granulate chemical products within a rotary "curtain-drum". The granules, which are partially recycled to the inlet of the drum, are lifted by blades (flights), thanks to the drum rotation, and fall back onto a properly designed fixed inner structure, which causes them to fall in the form of a falling curtain, onto which a concentrated solution (or a suspension or a melt) containing the product to be granulated is sprayed. The granules, onto which more product layers are deposited and solidified, leave the drum from the other end. Such granulation method does not allow however a high output; infact, the amount of granulated product is rather low. An object of the present invention is to provide a process for the granulation of chemical products, allowing to reach a higher output; one more object is to provide an apparatus suited to practise said process.